1. Field of the Invention
The present invention generally relates to communication systems and, more particularly, to packet based communication systems.
2. Background of the Invention
The Internet Protocol (IP) is a network layer protocol used for communicating data across a packet-switched communications network. In order to communicate using IP, session media (i.e. information) must be communicated using an IP compatible signaling protocol. Session Initiation Protocol (SIP) is one such protocol. SIP is an ASCII-based, application-layer control protocol that can be used to establish, maintain, and terminate calls between two or more communication devices (e.g. subscriber stations). With the proliferation of IP, SIP and corresponding infrastructure, IP and SIP are attractive networking resources to link various portions of a communication system.
In SIP, a communication device may request termination of a communication session, for example a call session, by sending a BYE request. When a BYE request is sent, SIP requires the communication device to immediately stop listening for session media. In certain types of communication systems, however, it is undesirable to allow a communication device to terminate an active communication session in this manner.